Hand truck



Dec. 19, 1967 L, c. GRIFFITH ETAL 3,353,863

HAND TRUCK Filed June 24, 1965 2 Sheets-Sheet l I INVENTORS ILORIN C. GRIFFITH GEORGE Z. (ONGOON Y Dec. 19, 1967 L, c. GRIFFITH ETAL HAND TRUCK 2 Sheets-Sheet 2 Filed June 24, 1965 INVENTORJ.

GRIFFITH g oncz L (0NGDON Dinah-u; .ffarlz'e Ahcrne s United States Patent Ofific e 3,358,863 Patented Dec. 19, 1967 3,358,863 HAND TRUCK Lorin C. Griiiith, Thiensvilie, and George L. Congdon, Fort Atkinson, Wis, assignors to S & G Enterprises, Inc, Miiwaukee, Wis, a corporation of Wisconsin Filed June 24, 1965, Ser. No. 466,605 8 Claims. (Cl. 214501) This invention relates to an apparatus for moving articles and more particularly to a hand truck for moving filing cabinets.

In large ofiices filing cabinets are usually arranged in side-by-side relation in a series or bank. Because of the weight and the limited access to the cabinets in the bank the cabinets are normally moved by initially emptying the contents, then pulling the empty cabinet out of the bank, loading the cabinet onto a truck for transporting to the new site, positioning the cabinet in the new site and then reloading the material back into the cabinet. In normal practice the cabinets have to be unloaded to be moved because the bank of cabinets is usually up against a wall and the cabinet to be moved cannot be tiited back in order to get the toe bar of a hand truck underneath the cabinet. Moreover, because cabinets are located to both sides of the cabinet to be moved in the bank the cabinet cannot be wiggled from side to side and moved out of the bank. Thus it is necessary in the conventional practice to unload the cabinet prior to removing it from the bank.

The present invention is directed to a hand truck for moving a filing cabinet and more particularly to a hand truck. which is capable of removing a loaded file cabinet from a bank or series of cabinets. The truck includes a frame having wheels for movement and a toe bar is mounted on one end of the frame and is adapted to be placed against the bottom edge of the cabinet to be moved. A vacuum cup assembly is attached to the end of an arm which is pivotally connected to the frame and the cup is positioned over the top surface of the cabinet at a location adjacent the front edge of the cabinet. The vacuum cup is applied manually to the upper surface of the cabinet, and a cam is operated through a lever to pivot the arm and lift the vacuum cup and the attached cabinet a slight distance off of the ground. Due to the position of the attachment of the cup to the cabinet the lower end of the cabinet will ivot forwardly over the toe bar against the frame. With the cabinet against the frame the truck can then be moved to the rear to remove the cabinet from the bank.

The lift truck of the invention enables a single cabinet to be removed from a bank of cabinets without the necessity of unloading the material from the cabinet. This saves the time which is normally required to remove the contents from each cabinet and then reinsert the material back into the cabinet after the moving operation. Moreover it is not necessary to move the adjacent cabinets in the bank when removing a single cabinet and this again saves time in the overall moving operation.

The suction or vacuum lifting device which is employed to lift the cabinet from the ground has a dual action which increases the effectiveness of the vacuum and the holding power of the vacuum cup. The vacuum cup assembly includes a lower plate which is applied to the upper surface of the cabinet and an upper plate is located in contact with the lower plate but is free of attachment with the lower plate. A flexible sealing member is secured against the outer surface of the upper plate and extends outwardly beyond the periphery of the plates to engage the surface of the cabinet and provide a seal therewith. The lifting arm is connected to the upper plate and moves the upper plate in a direction away from the lower plate to produce a gap between the plates as the lifting arm is actuated. The lower plate which is positioned against the cabinet is provided with a vent opening and as the gap between the plates is increased in size, the pressure in the gap is reduced and this reduction in pressure causes air between the cabinet and the lower plate to move through the vent hole to the gap to equalize the pressure and thereby increase the vacuum effect.

As an added feature, the wheels are mounted on a Wheel supporting structure which is pivotally connected to the truck frame. When a cabinet is being transported on the frame, the frame pivots relative to the wheel supporting structure so that the wheels are more nearly located under the center of gravity of the cabinet.

Other objects and advantages will appear in the course of the following description.

The drawings illustrate the best mode presently contemplated of carrying out the invention.

In the drawings:

FIGURE 1 is a side elevation of the hand truck of the invention;

FIG. 2 is a front view of the hand truck;

FIG. 3 is an enlarged fragmentary side elevation with parts broken away showing the lifting assembly;

FIG. 4 is a view taken along line 44 of FIG. 3;

FIG. 5 is a side elevation of the hand truck with the vacuum cup assembly engaging the cabinet;

FIG. 6 is a view similar to FIG. 5 showing the vacuum cup assembly in the raised position and the engagement of the cabinet with the frame;

FIG. 7 is a side elevation of the hand truck in the transporting position; and

FIG. 8 is a sectional view of the vacuum cup assembly.

The drawings illustrate a hand truck which is particularly adapted for moving filing cabinets and includes a frame 1 consisting of a pair of spaced channels or side rails 2 connected at one end by a toe bar 3 and at the opposite end by a cross bar 4. In addition, an angleshaped stop bar 5 is secured across the channels 2 at a locationadjacent the toe bar 3.

The hand truck also includes a wheel supporting structure, indicated generally by 6, including a pair of spaced arms 7 which are pivotally connected to lugs 8 on channels 2 by pins 9. An axle 10 7 and ends of the axle carry wheels 11. The wheel supporting structure 6 is pivotally mounted with respect to the frame 1 and pivotal movement of the wheel supporting structure 6 in one direction is limited by the engagement of the end of the arm 7 with a pair of stop blocks 12 which are secured to the channels 2. Springs 13 serve to urge the ends of the arms 7 into engagement with the stop blocks 12 and one end of each spring is secured to a bolt 14 on the channel 2 while the opposite ends of each spring is connected to a bolt 15 located on the end of the respective arm 7.

The hand truck includes a lifting unit 16 which is adapted to engage the upper surface of a cabinet 17 and lift the cabinet so that it can swing by gravity into engagement with the channels 2. As best shown in FIGS. 3 and 4, the lifting assembly 16 includes a pair of spaced plates 18 which are pivotally connected to the channels 2 by a spring pin assembly 19. The spring pin assembly includes a hollow tube 20 and a pair of pins 21 are slidably mounted in each end of the tube. A spring 22 located within the tube 20 between the pins 21 urges the pins outwardly. To prevent displacement of the pins from the tube 20 a screw 23 is secured to each pin 21 and extends outwardly through a slot 2 4 in the tube 20. The ends of the pins 21 are adapted to engage aligned holes 25 in the channels 2. As shown in FIG. 1, the channels 2 are provided with a series of holes 25 and the lifting unit 16 can be moved with respect to the channels 2 so that it is at a proper height for the cabinet 17 to be moved.

is journaled between the arms In addition, the upper ends of the plates 18 are connected together by a bolt 26.

An arm or boom 27 is mounted for pivoting movement between the plates 18 and the outer end of the arm 27 carries a vacuum cup assembly 28 which is adapted to be engaged with the upper surface of the cabinet 17. To pivot the arm 27 to thereby raise and lower the vacuum cup assembly 28, a cam 29 is pivotally mounted between the plates 18 by a bolt 30' and a handle 31 is connected to the cam and extends outwardly in a position where it can be engaged by the operator. The handle is adapted to move through an arc of 180 and when in the upper position, as shown in FIG. 1, the arm 27 and vacuum cup assembly 28 will be in the lowermost position. By pivoting the handle 31 downwardly, the cam 27 will ride on the inner end of the arm 27 to thereby pivot the arm and vacuum cup 28 upwardly. The outer end of the arm 27 is urged downwardly by a leaf spring 32 which bears against the inner end of the arm. The lower end of spring 32 is connected by a series of screws 33 to the upper end of a bar 34 which is pivotally connected between the plates 18 by a bolt 35.

As best shown in FIG. 4, a shaft 36 is secured within an opening in the lower end of bar 34 and a pair of angle brackets 37 are secured to the outer ends of the shaft 36 and are adapted to engage the channel shaped side rails 2. Welded to the inside of each of the angle brackets 35 is a handle 38 which extends rearwardly to a position where they can be grasped by the operator.

In addition to bar 34, a second bar 39 is secured by welding between the plates 18 and is located in alignment with the bar 34. One end of a bolt 40* is secured within an opening in the bar 34 and the opposite end of the bolt extends through a slot 41 formed in the lower end of bar 39. Knob 42 is threaded on the outer end of the bolt 40 and by threading the knob down, the bar 39 will be moved toward the bar 34 which is engaged with the channel 2 to thereby pivot the plates 18 and arm 27 relative to the frame 1. The adjustment provided by the knob 42 and the threaded bolt 40 provides a fine adjustment for the vertical position of the vacuum cup assembly 28. As previously mentioned, the channel 2 is provided with a series of holes 25 and the spring pin assembly 19 can be located in the proper aligned holes to position the vacuum cup slightly above the top of the cabinet to be moved. After the coarse adjustment provided by the engagement of the spring pin assembly 19 with the holes 25, the vacuum cup assembly 28 can be lowered into contact with the top of cabinet 17 by threading knob 42 on the shaft 40.

The vacuum lifting unit 16 includes a generally rectangular lower plate 43 having a rubber or resilient coating 44 applied to its lower surface so it will not mar or damage the surface of the cabinet 17 with which it is engaged. A second upper plate 45, also rectangular in shape, is located in flatwise engagement with the lower plate 43. Plate 45 has a substantially smaller dimension so that the peripheral edges of the lower plate 43 project outwardly beyond the corresponding edges of the plate 45.

Located over the plate 45 is a rubber or resilient sealing member 4, also rectangular in shape, and the edge or margin 47 of the sealing member 46 projects outwardly beyond the corresponding edges of the lower plate 43 and is sealed against the top surface of the cabinet 17. The sealing member 46 is flexible and when the vacuum lifting unit 16 is pressed downwardly against the cabinet surface the sealing member 46 will provide an air tight seal with the cabinet surface.

The upper plate 45 and the sealing member 46 are secured together by a series of bolts 48 and thus act as an integral unit, while the plate 45 is free of attachment to the lower plate 43. Bolts 48 extend through suitable openings in the web of a lifting yoke 49 and flanges 50 of yoke 49 are pivotally connected by a pin 51 to the outer end of the arm 47.

A retaining member 52 is positioned upwardly of the sealing member 46 and a series of bolt 53 connect the lower plate 43, the sealing member 46 and the peripheral edge of the retaining member 52. The outer edge of the retaining member 52, as indicated by 54, is bent downwardly and disposed in engagement with the peripheral edge of sealing member 46.

As shown in FIG. 8, the central portion of the retaining member 52 is provided with an opening 55 through which the flanges 50 of yoke 49 extend.

in operation, the vacuum lifting unit 16 is pressed down manually against the upper surface of the cabinet 17, spreading the edge 47 of the sealing member 46 outwardly and providing a seal with the cabinet. When the arm 27 is lifted upwardly, the upward movement is transmitted through the yoke 49 to the upper plate 45 so that the upper plate will tend to separate from the lower plate 43 and provide a chamber or gap therebetween. The lower plate 43, as well as the rubber coating 44, are provided with a vent hole 56 and as the plate 45 separates from the lower plate 43 a vacuum is created in the space between plates 43 and 45 and the air located in the space between the lower plate and the cabinet 17 will move upwardly through the vent hole 56 to equalize the pressure and thereby reduce the air pressure within the space between the plate 43 and the cabinet. Thus, the vacuum is progressively increased as the plate 45 moves upwardly which increases the holding action on the cabinet.

The retaining member 52 provides a stop which is en gaged by the upper plate 45 and the sealing member 46 and limits the upward movement of plate 45 with respect to plate 43. By limiting the upward movement of plate 45 the size of the space between plates 43 and 45 is correspondingly limited and this determines the vacuum which is developed.

To remove a cabinet from a bank, the truck is initially moved to a position in front of the cabinet to be removed with the toe bar 3 in engagement with the lower portion of the cabinet 17. The vacuum lifting assembly 16 is positioned above the top surface of the cabinet by adjustment of the spring pin assembly 19 with the holes 25 in the channels 2. Following this, the hand knob 42 is threaded down to pivot arm 27 and bring the vacuum cup 28 into engagement with the upper surface of the cabinet 17. The vacuum cup 28 is then pressed downwardly against the upper surface of the cabinet causing the periphery of the flexible sealing member 46 to seal against the surface of the cabinet. With the sealing member 46 in engagement with the cabinet 17, the lever arm 31 is moved downwardly which, through action of the cam 29, will pivot the arm 27 and raise the vacuum cup 28 to thereby elevate the cabinet 17 above the floor. As the lifting arm 27 is applied off center with respect to the fore and aft center line of the cabinet, as shown in FIG. 5, the cabinet 17, on being elevated from the floor, will pivot so that the lower front or forward edge of the cabinet will move into engagement with the channels 2 and the lower edge of the cabinet will swing above the toe bar 3. With the forward edge of the cabinet against the channels 2, the frame can then be titled downwardly and the truck moved to the rear to remove the cabinet 17 from the bank of cabinets. After removal, the cabinet can be transported, as shown in FIG. 7, to a new location. Normally, during transporting, the cabinet 17 will not be in engagement with the toe bar 3 but will be maintained in position on frame 1 by the holding action of the vacuum cup assembly 16. The toe bar functions primarily as a safety device and prevents the cabinet from sliding downwardly off the frame in the event the vacuum is accidentally released.

Due to the weight of the cabinet, the frame 1 will tend to pivot downwardly against the force of the springs 13 during transporting, as shown in FIG. 7, so that the arms 7 are arranged at an acute angle with respect to the channels 2. This positions the Wheels 11 more nearly toward the center of gravity of the cabinet 17 being transported on the truck and reduces the amount of weight required to be carried by the operator who will be holding the handles 38. The degree of pivotal movement between the channels 2 and the arms 7 is limited by engagement of the arms with the stop bar which extends across the channel members 2.

When installing the cabinet in a new location the frame 1 is tilted to beyond the vertical position causing the lower portion of cabinet 17 to pivot away from channels 2 so that the front of the cabinet is no longer located above the toe bar 3. The lever handle 31 is moved to the upper position which will pivot the arm 27 downwardly and lower the vacuum cup assembly 23 and thereby lower the cabinet 17 to the floor. The vacuum cup assembly 23 can then be removed from the top of the cabinet by prying up the edge of the sealing member 46 to release the vacuum.

The hand truck of the invention enables filing cabinets to be removed from a bank without unloading the material from the cabinet. This not only saves a substantial amount of time which would normally be necessary for loading and unloading the material but also eliminates the storage problems for the unloaded material and eliminates any possibilities of incorrect filing when the material is placed back into the fding cabinet,

The vacuum lifting unit which is employed to lift the filing cabinet from the floor has a dual action in which the magnitude of the vacuum is increased as the cabinet is elevated which thereby increasesthe holding power on the cabinet.

As an additional feature the wheel supporting structure is pivotally connected to the frame and this connection enables the frame to pivot relative to the wheels so that the wheels will be located more nearly under the center of gravity of the filing cabinet which is being transported on the frame.

Various modes of carrying out the invention are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention.

We claim:

1. A hand truck for moving articles having a smooth upper surface, comprising a frame, wheel means connected to the frame for moving the frame. an abutment located at one end of the frame, a vacuum lifting member disposed at the other end of the frame, means to adjust the position of the vacuum lifting member with respect to the frame and thereby engage the lifting member with the upper sur face of the article, and means for moving the vacuum lifting member toward and away from the abutment to thereby lift the article, the lower end of said article being tilted into engagement with said abutment in response to lifting of the article by said vacuum lifting member.

2. A truck for moving filing cabinets or the like, comprising a movable frame, a vacuum lifting unit disposed at the upper end of the frame and including an arm extending forwardly from the frame and having vacuum cup means pivotally connected to the outer end of the arm and disposed to engage the upper surface of the cabinet to be moved, and means associated with the rear portion of the arm for pivoting the arm to thereby lift the vacuum cup means and raise the cabinet from the floor whereby the lower portion of the cabinet will tilt into engagement with the frame in a position for transportation.

3. A hand truck for moving filing cabinets and the like, comprising, a frame, a wheel supporting structure pivotally connected to the lower portion of the frame and including a plurality of wheels, means for urging the wheel supporting structure to a position at an angle approximately 90 to the frame, a vacuum lifting device located at the upper end of the frame and including a vacuum cup adapted to be applied to the upper surface of the cabinet,

and means for elevating the vacuum lifting device to thereby elevate the cabinet above the ground, said cabinet swinging rearwardly into engagement with the frame in a position to be transported.

4. A hand truck for moving articles, comprising a frame including a pair of spaced generally parallel side rails, a toe bar located at the lower end of the frame and extending across the side rails, a vacuum lifting unit disposed at the upper end of the frame and including an arm extending forwardly from the frame over the toe bar and having vacuum cup means pivotally connected to the outer end of the arm and disposed to engage the upper surface of the article to be moved, means for adjusting the position of the arm with respect to the side rails in a direction toward and away from the toe bar whereby the position of the vacuum cup means can be varied depending on the height of the article, and cam means associated with the rear portion of the arm for pivoting the arm to thereby lift the vacuum cup means and raise the article from the floor whereby the lower portion of the article will tilt into engagement with the frame in a position for transporting.

5. A hand truck for moving articles, comprising a frame including a pair of spaced generally parallel side rails, a toe bar located at the lower end of the frame and extending across the side rails, a vacuum lifting unit disposed at the upper end of the frame and including a body section and an arm extending forwardly from the body section and having vacuum cup means pivotally connected to the outer end of the arm and disposed to engage the upper surface of the article to be moved, means for pivotally connecting the body section to thefrarne, means for pivotally connecting the arm to the body section, means for pivoting the body section with respect to the frame to thereby provide an adjustment of the position of the vacuum cup means toward and away from said toe bar, and means associated with the rear portion of the arm for pivoting the arm to lift the vacuum cup means and raise the article from they floor whereby the lower portion of the article will tilt rearwardly into engagement with the frame in a position for transporting.

6. A lift truck for moving filing cabinets, comprising a movable frame including a pair of spaced generally paral lel side rails, a lifting unit pivotally connected to the frame, said lifting unit including an arm extending forwardly from the frame with the central portion of the arm being mounted for pivotal movement with respect to the frame and said unit including vacuum cup means connected to the forward end of the arm and disposed to engage the flat upper surface of the cabinet to be move-d, and cam means associated with the rear portion of the arm for pivoting the arm to thereby lift the vacuum cup means and raise the cabinet from the floor, whereby the lower portion of the cabinet will tilt rearwardly into engagement with the frame in a position for transporting.

7. A truck for moving filing cabinets or the like, comprising a movable frame, a vacuum lifting unit connected to the upper end of the frame including an arm mounted for pivotal movement with respect to the frame and extending forwardly from the frame, said unit also including vacuum cup means pivotally connected to the forward end of thearm and disposed to engage the upper surface of the cabinet to be moved, said vacuum cup means including a sealing member having a flexible peripheral edge adapted to engage and seal against the upper surface of the cabinet, said arm extending outwardly from the frame a distance such that the sealing member will engage the upper surface of the cabinet at a position spaced from the center of gravity of the cabinet in a direction toward the frame, and means associated with the rear portion of the arm for pivoting the arm to thereby lift the vacuum cup means and raise the cabinet from the floor whereby the lower portion of the cabinet will swing into engagement with the frame into position for transporting.

8. A truck for moving file cabinets, comprising a frame, wheel means carried by the frame, a toe bar located at the lower end of the frame, a vacuum lifting unit disposed at the upper end of the frame, said vacuum lifting unit comprising a first generally rigid plate adapted to be applied to a flat surface of an article to be moved, a second plate disposed flatwise to the first plate and free of attachment to the first plate, a flexible sealing member disposed flatwise against the outer surface of the second plate and secured to the second plate, the periphery of said sealing member extending outwardly beyond the corresponding edges of the second plate and the first plate and adapted to engage the surface of the article and form a sealed chamber therewith, means connected to the second plate for moving the second plate in a direction away from the first plate to provide a space between the first and second plates, and vent means extending through the first plate and communicating between said space and said sealed chamber for venting air from said sealed chamber to said space to thereby reduce the pressure in the chamber and increase the vacuum affect.

References Cited UNITED STATES PATENTS 2,663,440

19/ 1953 Jackson. 2,713,463 7/1955 Gardner'et al 214-371 X 2,850,279 9/ 1958 Stoothott et a1 294-64 X 3,003,806 10 196 1 Shramek 294101 3,115,262 12/ 1963 Avery 294-65 3,207,348 9/1966 Olson 294-64 X 3,230,002 1/ 1966 Olson 29464 FOREIGN PATENTS 1,295,998 5/ 1962 France.

GERALD M. FORLENZA, Primary Examiner.

ALBERT I. MAKAY, Examiner. 

1. A HAND TRUCK FOR MOVING ARTICLES HAVING A SMOOTH UPPER SURFACE, COMPRISING A FRAME, WHEEL MEANS CONNECTED TO THE FRAME FOR MOVING THE FRAME, AN ABUTMENT LOCATED AT ONE END OF THE FRAME, A VACUUM LIFTING MEMBER DISPOSED AT THE OTHER END OF THE FRAME, MEANS TO ADJUST THE POSITION OF THE VACUUM LIFTING MEMBER WITH RESPECT TO THE FRAME AND THEREBY ENGAGE THE LIFTING MEMBER WITH THE UPPER SURFACE OF THE ARTICLE, AND MEANS FOR MOVING THE VACUUM LIFTING MEMBER TOWARD AND AWAY FROM THE ABUTMENT TO THEREBY LIFT THE ARTICLE, THE LOWER END OF SAID ARTICLE BEING TILTED INTO ENGAGEMENT WITH SAID ABUTMENT IN RESPONSE TO LIFTING OF THE ARTICLE BY SAID VACUUM LIFTING MEMBER. 